Silicon Valley is beginning to question its ties with Saudi Arabia. But there are many skeptics these days who privately question whether the relationship will actually change once the news of the day moves away from the Middle East.

Since the disappearance of a dissident journalist in a Saudi Arabian consulate, some of the most powerful figures in business are distancing themselves from the kingdom. There is one prominent exception: Masayoshi Son, chief executive of the SoftBank Group.

Blackstone, the firm which is relying on Saudi Arabia to provide half the money for its planned $40 billion infrastructure fund, waved off concerns about funding even as controversy rages over the disappearance of a Saudi journalist that has frayed relations between Wall Street and the oil-rich kingdom.

Saudi Arabia is preparing to double-down on its bet that Masayoshi Son can pick the technology giants of the future. The country's sovereign fund will make another $45 billion investment in Son's second massive Vision Fund.

Investing in private equity for the world's largest company has been a fascinating and challenging experience. Underlying my strategy are five foundational principles that I have studied theoretically, experienced professionally and believe in whole-heartedly. Once those building blocks are established, there are common mistakes that LPs must avoid on the path to building a model private equity portfolio.

Reconciling a sluggish global economy and all round uncertainty with rallying stock markets and tight spreads is preoccupying most minds today. While the market pundits seek to resolve the current di...